1. Field of the Invention
The present invention relates to a mobile phone, and more specifically, to a mobile phone that is capable of change its configuration state into at least two states, a closed state in which a microphone is covered with the casings and an open state in which the microphone is not covered with the casings, and that is capable of performing output control of speakers in accordance with a configuration state.
2. Description of the Related Art
Recently, as compact electronic devices become more sophisticated in functionality, the mobile phone has been openably/closably constructed by, for example, foldably or slidably stacking together a plurality of casings. As a result, the mobile phone is compactly accommodated in a closed state thereof during non-usage, while it is functionally used in an open state thereof during usage. However, when the mobile phone is openably/closably constructed, a microphone incorporated in a casing is covered with another casing, so that there has been a problem in that sound waves emitted from a speaker with the casings closed, is undesirably taken into the microphone.
With this being the situation, mobile phones are disclosed that prevent sound waves emitted from a speaker from propagating to a microphone, and one example of the disclosures is Japanese Unexamined Patent Application Publication No. 2005-142834. This type of mobile phone is a foldable mobile phone comprising a body cabinet having a microphone and a lid cabinet having speakers, the two cabinets being openably/closably connected. The lid cabinet has sound radiating holes formed inside it, and incorporates a shutter for closing the sound radiating holes. This mobile phone is configured so as to open the shutter with the cabinets opened, and close the shutter with the cabinets closed, thereby preventing sound waves from propagating to the microphone.
Currently, with the increased tendency of the mobile phone toward multimedia functionality, mobile phones having speakers such as stereo speakers provided at a plurality of places of the casing are on the increase. In such mobile phones, the speakers and the microphone are often forced to be closely located within the casings. In such mobile phones, when a video-phone call or handsfree talking is made, unwanted sounds from the speakers are undesirably inputted into the microphone, and therefore, these unwanted sounds are cancelled out using an echo canceller or the like.
On the other hand, casings with an opening/closing mechanism (such as foldable type, slide type, swivel type) mostly have a construction in which a microphone is covered with the casings closed. When making a video-phone call or handsfree talking with the casings having an opening/closing mechanism closed, unwanted sounds from speakers reflect on the casing covering the microphone, so that the sounds are inputted into the microphone at a sound volume level higher than that in the case where the casings are opened. As a result, the sound volume level of the unwanted sounds from the speakers exceeds the level up to which the sound volume can be removed. This causes a problem of reducing the sound quality or causing howling on a talking partner side.